On 06/06/2018 05:39 PM, Paul Koning via cctalk wrote: > Yes. "Same length wire" is how I first heard it. When I started reading the > 6600 wire lists I discovered that the reality is far messier. The PPUs > aren't too bad, that is a 4 phase clock, where consecutive stages are clocked > usually at 50 or 75 ns apart. For example, the consecutive stages of the > barrel are clocked (mostly) at 75 ns difference.
My project manager at the time was Mike Miller, who related that as an EE fresh from the U of Minnesota, his first job at CDC was measuring the coils of wire on the 6600 to which Seymour had attached a tag that said "tune". Some who had done early work as CEs related the differences between SN 1 and the regular production runs. Apparently, the floating-point divide unit gave results that weren't duplicated by any other 6600. Rick's story makes me wonder why nothing like that ever happened to the DD60s at Sunnyvale. Since the systems were essentially full of QSEs owned by Special Systems, a lot of dedicated block time for OS development was available. I've witnessed coffee and coke spilled into the things--and the ever-present ash tray on the side. We used to be invaded by masses of crickets when the weather got cooler--SVLOPS was surrounded by onion fields and bugs would find their way inside. You could find crickets happily camping in your desk drawers--and they got into equipment by the hundreds. A couple of the CEs had a pet mouse that lived under the raised floor--I don't recall his name. --Chuck
